Turbosmart’s OPR T40 – Turbo Oil Pressure Regulator

Turbosmart's OPR T40 – Turbo Oil Pressure Regulator


Turbosmart’s new patent pending OPR T40 is an oil pressure regulation system for your ball bearing turbocharger. It helps prevent compressor or turbine stage oil leaking or smoking, and takes the guesswork out of oil restrictor sizing for more efficient and effective oil delivery. Providing an aftermarket turbocharger with the ideal oil pressure has always been a challenge. Traditionally, the turbocharger’s oil feed has relied on a restrictor system, which are difficult to set up correctly. When incorrectly sized or set up, they can be the cause of turbo seal leakage and blow-by.

Turbochargers require a good source of oil and more specifically, turbochargers are built around a preference for a specific ‘window’ of oil pressure and flow. Generally, a ball bearing turbocharger assembly requires less oil to be reliable than a journal bearing system and this is actually one of the key benefits in its use on modern engines.



A turbocharger assembly has oil, hot exhaust gas and compressed air all within the tight confines of its core and this is where some compromises need to be addressed. The relationship between oil, exhaust & compressed air needs to be relative and that is because seals are in place to stop one from mixing with the other. A common misconception is that there is a ‘seal’ that stops oil getting into the inlet air or the exhaust gas and that is simply not the case. The seal is in fact, a gas ring and more resembles that of a common piston ring than any kind of rubber seal. Its function is to hold the exhaust gas or compressed air out of the oil system, not the other way around, as is often assumed. 

With the reduction in oil needs of a ball bearing turbocharger, there was a corresponding change in gas ring profile so that the balance of pressures fighting each other (exhaust gas, compressed air and oil) were maintained. This overall creates a beneficial system where less energy is consumed by seals and bearing assembly, resulting in a more responsive turbocharger.

However, engine oil pressure requirements within a modern engine are often higher than that of the turbochargers assembly and this is where a problem arises. Most of the engine requires a good steady feed of oil flow at high pressure for good efficiency and reliability while the turbocharger’s needs have reduced. The common solution, even at an OEM level, has been to fit a restrictor in the oil feed line to the turbocharger assembly.

The problem with this method, however, is there is a major difference between controlling flow and controlling pressure. The restrictor method that is most often used is actually an oil flow reduction method. What occurs is a compromise; reducing flow with a view to achieving a more suitable pressure, rather than directly reducing pressure to where it is needed. This method’s impact on oil pressure is also subject to oil grade, viscosity and supply pressure. A change in any of these variables has a huge impact on the resulting pressure and this is why this method can be tricky and cumbersome.



” It’s one of those solutions we’re truly proud to stand behind. Our guys came up with an innovative solution to a problem people have been frustrated by & barely coping with for years!”
– Chris Milne, Turbosmart UK’s General Manager.

This is where Turbosmart’s OPR T40 shines. It’s designed to regulate oil pressure without any impact on flow – simple as that. It’s able to achieve the desired oil pressure in the face of high supply pressure, at any temperature and resulting viscosity and does so without impacting flow. It is a true regulator and takes the guess work out of orifice sizing for oil supply and removes the need of the black art in the tuning of carefully balancing oil supply line size versus oil drain sizing for custom turbocharger fitment.

Turbosmart’s Turbo Oil Pressure Regulator ensures the oil pressure going to the turbocharger never exceeds the maximum pressure the turbocharger manufacturers specify for oil supply, regardless of engine oil pressure. The result is an oil delivery system that is more reliable and easier to setup than a standard restrictor system.

The OPR T40 can be used with a Turbosmart FPR gauge to monitor oil pressure levels. They are an ideal companion to Turbosmart’s new range of turbo fittings and oil feed filters, completing a new range of products that makes the safe and reliable operation of your turbo easier to achieve than ever.


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